Founded in 1996 by Environmental Resources Trust (ERT), ACR is a Non-Profit Organization and the first private voluntary offset program in the world.

In both the regulated and voluntary carbon markets, ACR oversees the registration and verification of carbon offset projects following approved carbon accounting methodologies or protocols and issues offsets on a transparent registry system. Each offset represents the reduction or removal from the atmosphere equivalent to one metric tonne of carbon dioxide. The offsets products are specific to ACR's distinct operations in the California compliance market, ICAO and the global voluntary carbon market.

In the voluntary Carbon Markets, ACR brands the verified emissions reductions (VERs) issued against ACR standards as Emission Reduction Tons, ERTs - one ERT represents the reduction or removal from the atmosphere equivalent to one metric tonne of carbon dioxide.

ACR has developed two standards:

• American Carbon Registry (ACR) Standard (version 7.0) that details ACR’s requirements and specifications for the quantification, monitoring, reporting, verification, registration and issuance of project-based GHG emissions reductions and removals as carbon credits. The Standard establishes the level of scientific integrity that every project must meet in order for ACR to register its GHG emissions reductions and removals as tradable environmental assets.
• ACR Validation and Verification Standard (version 1.1) required by an independent third-party. Verification is a risk-based process carried out in conformance with ISO 14064-3:2006 and ISO 14065:2007. ACR validation and verification bodies (VVBs) shall be accredited for project validation and verification and the scope of the applicable methodology, and VVB teams shall meet the competence requirements as set out in ISO 14065:2007.

Finally, ACR developed 17 methodologies, has two under scientific peer review, two for public comment, and one methodology under development.

Organizations or individual users may register and open an account in ACR by which the commit to pay a fee used to cover the program operations and administrative costs.

• ACR operates a robust and secure electronic registry system, powered by APX, for members to register California and voluntary market projects and record the issuance, transfer and retirement of serialized, project-based and independently verified offsets.
• The contracting of offsets for purchase or retirement takes place directly between buyer and seller through over-the-counter (OTC) transactions outside of the Registry system or on an approved, linked offset exchange. After a sale takes place, the counter-parties record the transfer of ownership or retirement of offsets within the Registry.

ACR registers offset projects from a wide range of project types including:

• Afforestation and Reforestation (A/R) of Degraded Lands
• Improved Forest Management (IFM)
• Avoided Conversion of Grasslands and Shrublands to Crop Production
• Restoration of California Deltaic and Coastal Wetlands
• Restoration of Pocosin Wetlands
• Destruction of Ozone Depleting Substances (ODS) and High-GWP Foam
• Use of Certified Reclaimed HFC Refrigerants and Advanced Refrigeration Systems
• Transition to Advanced Formulation Blowing Agents in Foam Manufacturing and Use
• Capturing and Destroying Methane from U.S. Coal and Trona Mines
• Landfill Gas Destruction and Beneficial Use
• Replacement of SF6 with Alternate Cover Gas in the Magnesium Industry
• Transport / Fleet Efficiency
• Recycling of Transformer Oil
• Carbon Capture and Storage

ACR operates in both global voluntary and regulated carbon markets.

REGULATED CARBON MARKETS

• Since December 2012, ACR has operated as an approved Offset Project Registry (OPR) for the California Cap-and-Trade program. In this role, ACR works with the Air Resources Board (ARB) to oversee the registration and issuance of California-eligible Registry Offset Credits developed using ARB’s compliance or early action offset protocols.
• In March 2020, ACR was approved by the Council of the International Civil Aviation Organization (ICAO) to supply eligible ACR-issued emission reduction units for compliance under the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA).

VOLUNTARY CARBON MARKETS

In the voluntary market, ACR oversees the registration and independent verification of projects that meet ACR's science-based Standards and follow ACR-approved carbon accounting methodologies, which ensure accuracy, precision and rigor in the measurement, monitoring and verification of emission reductions. ACR provides the flexibility of a wide range of methodologies that diversify offset sourcing options and demonstrate environmental benefits beyond emissions reductions.